Chapter 12 Flashcards
Explain the various ways in which frequency analysis can be used
Communicate the results of a study via univariate categorical analysis
Determine the degree of item nonresponse
Identify blunders
Identify outliers
Determine the empirical distribution of a variable
• What are the most commonly used measures of descriptive measures (measures of central tendency) for ratio scales?
The mean (pronounced x bar) is a measure of central tendency
What are the commonly used measures of dispersion for ratio scales?
The standard deviation (s) is measure of dispersion
Frequency Table
Always use percentages in frequency tables and related bar or pie charts
Researchers almost always work with “valid” percentages which are simply percentages after taking out cases with missing data on the variable being analyzed
Sometimes the cumulative percentages might be more appropriate for the discussion than the individual percentages
Outliers
In statistics, an outlier is an observation point that is distant from other observations. An outlier may be due to variability in the measurement or it may indicate experimental error; the latter are sometimes excluded from the data set.
Histograms
a diagram consisting of rectangles whose area is proportional to the frequency of a variable and whose width is equal to the class interval.
Cumulative Distribution Function
a function whose value is the probability that a corresponding continuous random variable has a value less than or equal to the argument of the function.
Testing Hypothesis
Specify Null and Alternative Hypotheses after analyzing the Research Problem
Choose an Appropriate Statistical Test
Specify the Significance Level for the Problem Being Investigated
Collect the Data and Compute the Value of the Test Statistic
Look up critical value from the table
Compare the computed statistic with the critical score obtained from the appropriate table and conclude
Null Hypothesis
Null Hypothesis (H0): The hypothesis that a proposed result is not true for the population
Alternative Hypothesis
Alternative Hypothesis (HA): The hypothesis that a proposed result is true for the population
Chi Square Goodness-of-fit test
A statistical test to determine whether some observed pattern of frequencies corresponds to an expected pattern.
Two Box Technique
A technique for converting an interval-level rating scale into a categorical measure usually used for presentation purposes. The percentage of respondents choosing one of the top two positions on a rating scale is reported.
